/*
 * FreeGLUT Shapes Demo
 *
 * Written by Nigel Stewart November 2003
 *
 * This program is test harness for the sphere, cone 
 * and torus shapes in FreeGLUT.
 *
 * Spinning wireframe and smooth shaded shapes are
 * displayed until the ESC or q key is pressed.  The
 * number of geometry stacks and slices can be adjusted
 * using the + and - keys.
 */

#include <GL/glut.h>
#include <math.h>
#include <stdlib.h>

static int slices = 30;
static int stacks = 30;

/* GLUT callback Handlers */

//Data Members
double xPos = 2.4;
double yPos = 1.2;
double zPos = -6.0;
double red = 0.1;
double green = 0.2;
double blue = 0.4;
double number = 0.0;


static void resize(int width, int height){
       
    const float ar = (float) width / (float) height;
    
    glViewport(0, 0, width, height);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glFrustum(-ar, ar, -1.0, 1.0, 2.0, 100.0);
    
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity() ;
    
}

static void display(void){
       
    const double t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
    const double a = t*90.0;

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    
    //Modify color for nice look
    if(red>=1){
        red /= 3;         
    }
    if(red<1 && red>=0){
        red *= 2;         
    }
    if(green>=1){
        green /= 2;         
    }
    if(green<1 && green>= 0){
        green *= 8;         
    }
    if(blue>=1){
        blue /= 7;         
    }
    if(blue<1 && blue >= 0){
        blue *= 4;         
    }
    
    glColor3d(red,green,blue);
    
    /*//Modify x and y using sin and cos
    if(number<1 && number>= 0){
        number += 0.01;         
    }
    if(number>=1){
        number -= 1.01;         
    }
    xPos = number;
    yPos = sin(xPos*4.584);
    */
    glPushMatrix();
        glTranslated(xPos,yPos,-6);
        glRotated(60,1,0,0);
        glRotated(3*a,4,2,6);
        glutSolidTorus(0.2,0.8,slices,stacks);
    glPopMatrix();

    glutSwapBuffers();
}


static void key(unsigned char key, int x, int y){
       
    switch (key) 
    {
        case 27 : 
        case 'q':
            exit(0);
            break;

        case '+':
            slices++;
            stacks++;
            break;

        case '-':
            if (slices>3 && stacks>3)
            {
                slices--;
                stacks--;
            }
            break;
        case 'w':
             yPos += 0.03;
             break;
        case 's':
             yPos -= 0.03;
             break;
        case 'a':
             xPos -= 0.03;
             break;
        case 'd':
             xPos += 0.03;
             break;
    }

    glutPostRedisplay();
}

static void idle(void){
    glutPostRedisplay();
}

const GLfloat light_ambient[]  = { 0.0f, 0.0f, 0.0f, 1.0f };
const GLfloat light_diffuse[]  = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_position[] = { 2.0f, 5.0f, 5.0f, 0.0f };

const GLfloat mat_ambient[]    = { 0.7f, 0.7f, 0.7f, 1.0f };
const GLfloat mat_diffuse[]    = { 0.8f, 0.8f, 0.8f, 1.0f };
const GLfloat mat_specular[]   = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat high_shininess[] = { 100.0f };

/* Program entry point */

int main(int argc, char *argv[]){
    
    glutInit(&argc, argv);
    glutInitWindowSize(640,480);
    glutInitWindowPosition(10,10);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("Amazing Shapes");

    glutReshapeFunc(resize);
    glutDisplayFunc(display);
    glutKeyboardFunc(key);
    glutIdleFunc(idle);

    glClearColor(1,1,1,1);
    glEnable(GL_CULL_FACE);
    glCullFace(GL_BACK);

    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);

    glEnable(GL_LIGHT0);
    glEnable(GL_NORMALIZE);
    glEnable(GL_COLOR_MATERIAL);
    glEnable(GL_LIGHTING);

    glLightfv(GL_LIGHT0, GL_AMBIENT,  light_ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE,  light_diffuse);
    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);

    glMaterialfv(GL_FRONT, GL_AMBIENT,   mat_ambient);
    glMaterialfv(GL_FRONT, GL_DIFFUSE,   mat_diffuse);
    glMaterialfv(GL_FRONT, GL_SPECULAR,  mat_specular);
    glMaterialfv(GL_FRONT, GL_SHININESS, high_shininess);

    glutMainLoop();

    return EXIT_SUCCESS;
}

